


Loving Lisa

by Anonymous



Category: The Simpsons
Genre: Breeding, Dead Dove: Do Not Eat, F/M, Impregnation, Incest Kink, POV Second Person, Porn With Plot, Reader-Insert, Sibling Incest, Teen Pregnancy, Teen Romance
Language: English
Status: In-Progress
Published: 2021-02-20
Updated: 2021-03-01
Packaged: 2021-03-16 14:49:25
Rating: Explicit
Warnings: Underage
Chapters: 9
Words: 20,301
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29577771
Author URL: https://archiveofourown.org/
Summary: You could tell you just had just fallen for your best friend, your little sister Lisa.
Relationships: Bart Simpson/Lisa Simpson
Kudos: 29
Collections: Anonymous





	1. The Hard Road

**Author's Note:**

> This story is marked "dead dove" for a reason. If you're stupid enough to actually try anything seen here then you deserve what's coming to you.

**Loving Lisa**

**Part One:** **The Hard Road**

When you woke up as Bart Simpson you weren’t sure what to do; Bart was an idiot and an underachiever. You might not have been a great achiever in a previous life, but you weren’t that level. Thankfully, you do like explosions, and fireworks and dangerous things like that, so when you turned to chemistry to further that… skill, people just dismissed the changes as you having found a passion.

A dangerous passion, but a passion none-the-less.

Milhouse just faded into the background. He was 10 and a bit annoying (not that it was his fault), but you couldn’t keep up that charade. Strangely, you found your sister became your best friend. She might have been two years your younger, but Lisa was bright and more like her earlier depictions than the later; smart but still willing to muck about on occasion. She pretended to not care, but it was clear she enjoyed your chemistry with you and secretly did like the crack of fireworks and the refinement of the art through many hours of research and construction.

It was comfortable, mostly because the characters around you were less a caricature and more real people. Dad was a bit bumbling, a bit simple and maybe too naïve, but he did scrap through college and become a reactor operator. Thankfully, he didn’t operate a reactor by himself.

Mom was perhaps closest to the tv series that you could remember, but she was also the least caricatured of the family. She had her hobbies and were preparing to start part time work again now Maggie would soon be old enough for preschool.

Grandpa was an old man, set in his ways, raised on stories of the glory days of America. He wasn’t nasty, just a bit ignorant. It was sad to see the world sweep by him.

It was comfortable, and the years passed. You put together a reasonable nest fund exploiting some sort-of future knowledge like cryptocurrency and recessions. You aged and your friends seemed to drop off, the only one sticking by being Lisa. You didn’t have a problem saying she was your best friend. You could talk with her all day about how you’re going to improve the fireworks you made, or how you’re going to make some chemical you need for some project. She’s fun to be around.

You were fourteen when you realize how fucked you are.

You stepped out of your bedroom and saw Lisa literally butt naked in the hallway. She’s looking the wrong way, her eyes on mom and dad’s door, her old clothes in her arms. She has a cute bum, and her hair is still wet from the shower.

All you can say is “oh” in surprise and Lisa jumps at the noise.

She tries to turn mid-air, a look of shock on her face. The bundle of clothes in her arms isn’t low enough to cover her crotch and she realizes this, pulling them down to cover it up, only to expose her breasts. They’re cute, they’re not huge but they are the right size for her petite frame.

“Bart!” Lisa shouts fearfully.

You snap away from your ogling and realize what you just did.

“Sorry!” you say, turning around.

As you hear Lisa run to her room, you turn back to yours, walking a bit stiffly, your erection tight in your pants. You do feel guilty about seeing her like that but there’s another problem: you _don’t_ feel guilty about being attracted to her. There’s no revulsion or shame, it just feels… right. She’s your best friend and sister, you love her, and well…

You could tell you just fell for your best friend, _your little sister Lisa._ You were fucked.

<^><^>

“Lisa?” you call, knocking on her door fifteen minutes later. “Sis?”

You don’t want this to come between you, and even if it weren’t for the fact it would scuttle your crazy thoughts of being able to love her, you don’t want your _normal_ relationship ruined either.

After several seconds you don’t get an answer and push the door open a bit.

“Lisa?” your ask worriedly.

“Bart,” comes Lisa’s quiet reply.

She sounds hurt, but you take her response as an invitation. Lisa is on her bed dressed in her PJs, lying on her side away from you, looking at her phone.

Making the decision you carefully close the door and slowly walk around her bed. There’s no seat so you take a seat on the carpet in front of her, putting yourself at the same level. She doesn’t make eye contact, and just stares at her phone, but you can see her red eyes and know she’s been crying.

There’s a good twenty seconds of silence before deciding you have to speak first.

“You okay, Lis?” you ask with worry.

Lisa shakes her head, her eyes making contact with yours for the first time since you entered the room. She sniffles and you can tell she’s suppressing a sob.

“I’m sorry, Lisa,” you say contritely. “I… I shouldn’t have perved on you like that.”

There’s no recognition in Lisa’s eyes at your apology. You’re suddenly worried that you’d screwed this up when Lisa spoke.

“Y-you’ve got nothing to apologize for, Bart.”

She drops her phone to the bed, her hands laying there loosely. With some hesitation you reach out and take one. She doesn’t pull away, so you try and convey the comfort and warmth you want to give her through the connection.

“I upset you, I want to make up for it.”

She shakes her head.

“It’s not your fault.”

You frown before shuffling a bit closer, resting your chin on the edge of her mattress.

“Then whose fault is it, who have I got to beat up for my little sis?”

She looks sadder at your offer. You’re worried she’s going to cry again and this time there would be no doubt it was your fault.

“You can’t fix this with hitting people,” she says thickly.

“I want to help you Lisa.”

She shakes her head again and sobs. She tugs her hand out of yours before rolling over to face the other way.

“I’m hideous,” she cries. “I’m ugly.”

That comes at a surprise; you couldn’t imagine something thinking Lisa was ugly of all things. It does not compute. It’s utter nonsense.

You mean _yeah_ , she’s not some drop-dead supermodel… but she’s twelve. She’s got a cute face with a button nose. Her bum – which you’re sure wasn’t like that six months ago – is respectable for someone her age and the same goes for her boobs. You know about the bum for certain because it’s right in front of you.

“You’re the cutest girl I know, Lisa.” Your own sadness as Lisa’s low self-worth leaks through. You don’t need to lie.

“You’re just saying that,” comes the muffled response back.

It’s painful to watch. So painful in fact that you’re half-temped to admit you find her attractive right there and then. You shouldn’t though and you’re doubtful that will make the situation any better. After a moment’s hesitation, you climb up on the bed and lie behind her.

Maybe you don’t need to admit all of it.

“You really are Lisa. No joke, cross my heart and hope to die I mean it you’re the cutest girl I know.”

There’s a moment before Lisa rolls back to face you. The tears are following freely, and you can’t help but wipe on running down Lisa’s nose off with a finger. She doesn’t seem happier though, she just frowns with sadness radiating off her.

You try for a bit more.

“When… I went back to my room, I… I felt disappointed when I remembered my cute best friend is my sister and I’m not allowed to ask her on a date.”

There’s a small amount of surprise in her eyes as you say those words before it morphs into doubt.

“You-you’re kind Bart to say that t-to me,” she says thickly.

You give her a small kind smile.

“But I – I know you’ll say anything to make me feel better.”

You deflate slightly. Lisa isn’t exactly wrong, but in this case it _is_ the truth.

“I’ll prove it,” you say without thinking.

You regret it almost immediately after it as you can’t _think_ of anything to prove it with.

Lisa looks surprised at the suggestion though.

“H-how?” Lisa asks, mirroring your own internal question.

“I – uh,” you uselessly respond.

The only thing that springs to mind is something utterly crazy like kissing Lisa. But this is real life, kissing your sister like that _doesn’t_ work.

Still, you do briefly consider it… _imagine it_ really. You could kiss her, taste her. You would pull her close, feel her breasts pressed against you and she could feel how hard she was making you. All you had to do was lean in closer…

You freeze, eyes wide in shock of yourself. Lisa is staring back at you in shock herself. There’s a beat before you recoil back a safe distance and shuffle to the edge of the bed for good measure. You had been _so_ close.

“Sorry, I – uh,” you say, desperately trying to think of an excuse. “I-I wasn’t thinking,” you eventually admit quietly, flaming red.

Lisa stares back into shock for several seconds before blushing.

“Oh,” is all she gets out, eyes fixed on you.

You’re wondering if you should go, but all Lisa is doing is staring, the shock still on her face. She hasn’t said a word, either positive or negative. Then, to your surprise, she takes your hand again. You can feel it shaking slightly.

“Thank you, Bart,” Lisa says sincerely. She still looks shocked.

You fall into a comfortable silence before you hear mom shout from the kitchen and you both regretfully get up.

You’re standing a foot apart from her. She looks ridiculously cute in her PJs and her slightly messy hair. You want to say as much and then sweep her into a kiss but when Lisa moves, she just envelopes you into a hug. As you wrap your arms around her in return you stand there comfortably, satisfied you have this at least.

<^><^>

As much as you fantasize about it, Lisa does not sneak into your room in the dead of night and confess her love for you.

What does happen is you wonder if Lisa was staring at you or watching you. You want to hope she’s interested, but you’re also aware you’re far too hopeful and you are probably imagining it. So all you do is take all the opportunities you can to watch Lisa. You’re worried to be seen staring too much, so you still avert your eyes, but you’re not sure you’re doing a good job of it.

It feels stupid to say it, but you’re certain you’ve fallen in love with her. You love her, but it’s going to cause all sorts of troubles; all you can do is imagine disaster at every turn trying to pursue it. Still, you do research on the topic, look up laws, the risks, but you’re not sure if you’re trying to persuade or dissuade yourself from this.

What is nice is you’re sure Lisa is happier and more confident after the assurance she’s not ugly. Maybe being told that you’re so pretty that your own brother can admit it does wonders for one’s confidence?

“But mom!” said Lisa. “I’m not a kid anymore.”

Mom gives Lisa a worried look from where she’s making breakfast and Maggie is watching the conversation between her older sister and mom.

“I’m not sure _thirteen_ is old enough to buy you a bikini, Lisa.”

Lisa meets your eyes for a moment, and you give her the tiniest of smiles. You’re pretty sure she knows you just imagined it.

Lisa’s birthday had been a few weeks ago. She’d invited a few people from school, but you swore she’d been most happy eating left-over cake with you afterwards.

“It’s not much different from a bra.”

Mom’s worry changes at Lisa pronouncement. Maybe she thinks Lisa might try wearing a bra at the pool instead of her _kid_ swimsuit? You wouldn’t mind seeing either.

“Hmm.”

Your mom glances at you.

“We can discuss it later,” say mom, clearly uncomfortable about the topic with you in the room.

Over the weekend Lisa accompanies mom shopping and she seems pleased with herself when she gets back. It’s now summer and you’re sure there will be an opportunity to ogle your little sister.

“Hey Bart. I asked mom and she said we can go to the pool tomorrow,” said Lisa after dinner one night.

“Oh, really?” you reply, looking up from your computer.

Lisa’s in her PJs. They’re a little bit too small for her, but she looks awfully cute in them.

“Yep. We’ll have to walk though; mom is doing stuff tomorrow.”

Springfield isn’t huge, so walking across town is easy.

“Oh, cool.”

Lisa just stands there, a small smile on her face, and you stare back. You’re sure there are things you both want to say but aren’t sure how to voice them.

“Well, tomorrow then. Nice and early?”

You nod and she gives you a smile.


	2. Turning Heads

**Loving Lisa**

**Part Two:** **Turning Heads**

“Bart?” comes Lisa’s voice. “Can you come in here a moment?”

You’ve got swim shorts and a t-shirt on and have packed a bag with the things you’ll need for the pool. Leaving the bag by your door you go to Lisa’s room and halt dead in your tracks in her doorway.

She’s standing in front of her mirror in a pastel pink and white bikini. It’s not a true bikini; it’s got bottoms that are more like a set of very short boardshorts instead of underwear, but she still looks incredible in them. You can see Lisa is blushing slightly in the mirror.

“Wow,” you admit quietly.

Lisa turns side on and gives you a nervous smile.

“Does it look good?”

You nod, blushing yourself. You nervously swallow, figuring that this isn’t any more than you previously had admitted to.

“I’m… going to be jealous of all the boys that show an interest in you,” you admit hesitantly.

Lisa blushes harder in response, a wide smile on her face. It’s the first time since that day that either of you have mentioned your admission.

Again, you both fall silent, waiting for the other to say something.

“So, want to get going?” Lisa asks.

You nod.

Lisa doesn’t object as you watch her from the doorway, grabbing her bag and throwing a few things into it. Lastly, she grabs a white t-shirt and throws it over her head. Then she heads towards you and the door.

Her hand reaches out and you take it. She gives it a squeeze and then stops in front of you. She looks nervous, nibbling on her lip and again you want to pull her close and kiss her deeply, but a part of you is still terrified of ruining this, ruining everything between you. Before you make up your mind though the moment is over and Lisa’s hand slips from yours. You follow her out of the house.

The start of summer, the pool is full of kids and adults of all ages. You and Lisa pay the entrance fee and then find a locker to store all of your stuff in. She’s standing right next to you as she pulls the t-shirt off over her head and throws it in with the rest of the stuff. Her eyes on you, her face tinged a pleasant pink, Lisa doesn’t make a single objection as your eyes trail up her body, over her breasts and to her pretty face. Your heart hammering away, this is another moment where the stupid part of your brain is telling you to kiss her, but you’re surrounded on all sides by other people, _people you know_.

Instead, you try to get in the pool before your erection gets too obvious.

<^><^>

It’s well past lunchtime and you’re both hungry when Lisa suggests you head back.

There had been many scantily clad bodies at the pool but you only had eyes for your little sister. Going by how often Lisa glanced back, you’re sure she knows. You’re finding it increasingly hard to care about her knowing you’ve been watching and you’re almost certain she’s enjoying it.

Though you both had towels, given the warm weather neither of you did much to actually dry off, just throwing t-shirts back on. Lisa’s shirt is thin enough that it’s quite transparent when wet and you glance down at her breasts every so often as you walk home.

Lisa is chatting about a science project she’s working, and you offer her some ideas. You make a good team bouncing ideas off each other, but neither of you try to push into each other’s projects.

“What do you want for lunch?” you ask.

If there’s one thing you brought from a previous life, it’s being a decent cook.

Lisa’s thoughtful for a moment before her eyes brighten.

“Can you do an omelet? You know, the ones with the feta and the tomatoes and the spinach?”

“Yeah, I can do that,” you answer.

You did have to brush up on your vegetarian skillset though. You would probably go full vegetarian if Lisa asked you too, if only for her.

Lisa smiles brightly at you.

When you get back to the empty house she grabs your bag to take upstairs as you get to work making lunch.

Your preference is light omelets so that means whipping air into the egg batter. Thankfully, the invention of electricity makes that easy. The other is frying and then grilling the top of the omelet in the oven before folding. It doesn’t take long, and you make enough to share. Lisa comes back at this point and you find yourself immediately stuck to the spot.

She’s still wearing the damp t-shirt, but she’s taken her bikini top off. She knows full well what she is doing going by the light blush on her cheeks and you can feel your heart hammering away. Your throat almost feels like it’s closed off and you’re not sure you’ll actually be able to eat.

You give up. You’re throwing away your objections.

“Would you… like to share a plate?” You’re not sure your voice has ever been this thick and it’s a miracle you can even talk.

Lisa might not be able to either given all she does is nod.

You grab a large plate and place the omelet on it, and then grab the cutlery. Lisa is at the table and you place the plate between her and the seat next to her. You heart is still hammering away as you sit next to her.

As much as you want to ignore the food and kiss her, you do need to have a serious talk, a talk about how you can make this crazy thing work between you. You _want_ it to work, you want this to be set for life. You want Lisa to be yours, to kiss her, to make love to her, to marry her and to have babies with her.

You freeze in your seat at the image of a pregnant Lisa coming up the isle for you in a wedding dress. Another nervous swallow.

“We… should eat before this goes cold,” you say grabbing some cutlery.

Lisa’s hands are shaking as she reaches for her own set of cutlery. A thought occurs to you as you cut a chunk off. Catching Lisa’s eye, you raise the fork towards her. Realizing what you are doing she abandons her shaking cutlery and lets you put the food in her mouth, surprise in her eyes. Your eyes are on her lips as she chews, and you thank the presence of food deterring you from kissing her there and then.

You take your own bite before feeding Lisa again. This goes back and forth for several rounds before Lisa takes her own cutlery with only slightly shaking hands. She feeds you first.

It strangely romantic and strangely close. It’s nice and you want to call it loving, but you’re not sure how far this extends on Lisa’s end.

“I’m full,” says Lisa as she tries to give you two in a row and the last piece.

You hold up two fingers, the pressure on the fork stops Lisa’s advance. You feel cheeky as you push it towards Lisa, a moment of sibling comfortableness in this whirlwind of emotions. Quickly she relents, the tiniest fraction of a glare in her eyes.

It’s not messy as she eats, but you’re sure there’s a small amount of food on the edges of your mouth just as you can see on Lisa’s. As she finishes you reach a finger out to wipe it off. Lisa freezes, her eyes on the fingers for a moment before glancing at you and then back to the fingers. She doesn’t object as you wipe both corners but there’s a moment of surprise in her eyes as you lick the food off your fingers.

You _need_ to talk before you both jump into this, but neither of you can help it as you lean into each other. Lisa’s eyes flick to your lips and then back to your eyes and then your lips connect. Both of you having waited so long immediately deepen the kiss, you tongue intertwining with Lisa’s. You’re sure you both groan in pleasure as your hands find her waist, pulling her more face-on to you.

There’s a few more seconds of passionate kissing before you can wait no longer, your hands slipping under Lisa’s t-shirt. You can smell the pool as your hands go up her stomach and chest before cupping her small breasts. They feel wonderful in your hands and Lisa whines into your mouth as you give them a careful squeeze. Then you brush your thumbs over her nipples.

Lisa gasps, her lips separating from yours. She has a mixture of amazement and shock on her face as you stare back into each other’s eyes.

“Was that okay, Lisa?” you ask quietly.

Her response sounds almost a pitch higher than usual.

“Yes,” she gasps out.

You do it again and Lisa gives a sharp, shuddering breath.

God, you love her.

The words in your mind are a tether back to reality.

“We… should talk about this,” you say hesitantly.

You don’t trust yourself and let your hands slip back down to Lisa’s waist. There’s a mote of disappointment in her eyes.

“We should,” she agrees quietly.

With a glance around the kitchen, you decide it should be done somewhere else, if only to avoid having sex on the kitchen floor.

“Would you like to go to your room?”

Lisa chews on her lip a moment.

“Yeah.”


	3. No Turning Back

**Loving Lisa**

**Part Three:**

**No Turning Back**

Lisa sits cross legged on her bed and you take a seat opposite. She looks nervous and unsure again and it’s painful to see. Still, you are the one who said they needed to talk and you did spend a long time thinking about this.

“I… want this to work, Lisa,” you admit.

You can’t hide the frown and the worry on your face. Lisa seems surprised though before he face twists to uncertainty again.

“What do you mean by work?”

You give a small uncertain shrug.

“Like, I want to date you… properly.” You’re not sure how far to admit it though. “I don’t want this to just be mucking about.”

Lisa slowly nodded.

“It –” you nervously swallow. “It won’t be easy.”

Lisa pauses. You’re not sure she’s thought that through completely. There’s her own nervous swallow before nodding.

“Yeah,” she simply says.

You give her a sad smile. This is going to be very difficult.

“Our… dates will – will just have to look like two siblings. Maybe if we go somewhere far away where no one knows us we can be a couple, but otherwise we have to hide everything.”

There’s another nervous nod from Lisa.

“At least we like camping, right?” says Lisa with a nervous laugh.

You join her at the actually not funny comment.

“Yeah.”

You hadn’t thought about camping, but she was right. It helped you were both mostly introverts and would enjoy camping in the woods together. Or any other introverted date you could come up with.

“Mom and dad can’t know,” Lisa breathed, her eyes off out the window.

You glance there yourself even though you know no one should be able to see you from the back of the house.

“No… if I’m lucky I’ll just be sent to live with Aunt Patty and Aunt Selma.”

You both look a bit sick at that, and that’s the _best_ outcome.

Trying to push _that_ thought away, you shuffle closer. Lisa looks at you and seeing what you doing offers her hand.

“So, you still want to do this, Lisa?”

You can see her eyes are a bit wet. You give her hand a squeeze and she nods.

“Yes, Bart.”

You just stare at each other a moment before you both shuffle closer again. You take a moment to reach out and push a strand of hair behind her ear. Her hair is blond like yours, but it’s a sort of short, elegant mess.

“Can I ask, what made you want this?” you ask her.

A small blush returns to her cheeks.

“I-I was sort of weirded out at first. It was... flattering, but… strange,” she admits. “I was trying to figure out what sort of girl you liked… maybe so I could help you find someone – as thanks. Then I…” Lisa nervously shuffles. “I tried to figure out what I liked, and then – well – it was you… the perfect boy was you.”

Even though you’d passionately kissed and just agreed to date, she’s nervous at the admission.

“I – well – my weirdness at it sort of faded. I –” Lisa blushed suddenly. “I had some dreams.”

You couldn’t help but smile at Lisa’s admission and she gives her own nervous smile in response.

“Would you tell me them?” you ask.

Lisa goes wide eyed and blushes more.

“Nooo,” she whines in embarrassment.

You give a laugh at her expression and a comforting hand-squeeze. She leans into you and hides her face in your chest. You run your free hand down her back in response.

“I might have had a few dirty dreams about you too, Lis,” you admit.

There’s a small shudder you can feel through her back at your words. You’re pretty sure it’s a pleasurable one.

Lisa has a small smile when she sits back up a few minutes later.

“Can you… tell me what you were thinking?” she asks.

You open your mouth to say something before closing it again to consider the question.

“I… I guess seeing you in the hall made me realize you weren’t _just_ my little sister and best friend.” Lisa smiles at you calling her your best friend. “It made me realize you’re beautiful and incredible… and – well – a girl.” You nervously shuffle as Lisa tries to be offended at only realizing it then. “I couldn’t keep my eyes off you, and – well – I already loved you as my sister and best friend, and it was only another small step to just… _love you_.”

Lisa’s eyes go wide at the admission.

“I think I’m madly in love with you, Lisa,” you quietly admit.

Lisa gives several deep, quick breaths, then she nods with a smile on her face, and then she starts crying. _Happy_ crying. You shuffle closer, a hand on her cheek. It takes several minutes for the tears to stop flowing, this wonderful shimmer in her eyes, only inches away from yours.

“I love you too Bart,” she eventually says.

Her smile is wide, genuine and infectious.

“How much?” you cheekily ask.

She looks like she’s about to answer when she changes track.

“How much do you love me?”

You come up short, a small part of your mind telling you not to admit it. But having see Lisa cry with joy only moments before you push it away.

“I’d marry you right now if I could.”

There are a few big slow nods before Lisa is crying again. You can’t help it and you pull her into a kiss again. It’s wet but soft and slow. Utterly tender and loving.

“This is crazy, but it feels so right,” says Lisa in amazement.

You nod back.

“I know,” you reply in your own wonderment.

It’s so unreal you’re back to just staring at each other again. It’s a comfortable silence.

“Would you like to trade… questions?” Lisa asks several minutes later. “Like… when you asked about my dreams. One question each, taking turns.”

You nod.

“Who goes first?”

Lisa takes a moment before saying “I will.”

Lisa clearly doesn’t have an immediate question in mind, so you let her think.

“Have… you kissed anyone besides me?”

You shake your head.

“I don’t get out much,” you say, looking Lisa over.

You’re tempted to ask the same question back, but you’re less curious about that than the original question.

“Describe your most recent dream involving us.”

Lisa knew this would be coming but still blushed.

“We… we were at the pool, but it was empty. It was just us. You were flirting the whole time and then it just sort of happened, we were kissing.” Lisa paused but you doubted this was the end.

“Was this dream… last night?” you ask.

Lisa nods with a blush and a small smile.

“We ended up in the paddling pool… I was… on my back,” Lisa said the last three words in a breathless whisper. “I had my legs around you. We were kissing and you were… _grinding_ against me. Then my bikini is off and you’re…” Lisa shuffled slightly; you could see her push her crotch across the bed just a fraction “… sucking my breasts.”

Lisa gave a nervous gulp.

“We were then – we had sex.”

You give her a comforting squeeze and a wide smile. She seems slightly relieved at it.

“The water was – well – nice.”

You give a small laugh.

“We can try it sometime,” you suggest.

Lisa has a happy blush at the suggestion.

“Your turn,” you say.

Another few seconds go by as Lisa thinks.

“What is the first dirty thing you can think of, right now, to do?”

Yeah, you know what.

“I want to eat you out,” you say bluntly.

Lisa looks surprised.

“R-really?” amazement tinging her voice. “Isn’t that… dirty?”

You roll your eyes affectionately; Lisa _had_ said dirty.

“Dirty and hot,” you say as Lisa realizes with a blush what she had just said. You’re fidgeting, imagining it a bit too much. “I want to eat you out and make you moan my name.”

Lisa blushes immediately.

“There… aren’t many things hotter than that. Hearing your voice… feeling your hips moving, _knowing_ I’m making you feel that good. That… that makes my heart race.” You say it with complete honesty. There’s something about _knowing_ you can make a girl feel that good, make her into warm putty in your hands.

Lisa’s blushing more furiously than ever, giving a few nods like she’s just learnt some basic fact of the universe is wrong. She looks like she’s ridiculously turned on too, like she wants friction on her crotch but doesn’t want to be seen actually doing it, instead settling for pressing her crotch down on the bed slightly.

“Are you imagining it right now?”

Lisa’s movements freeze. She nods.

“How does it feel?”

She blinks at you, perhaps not sure if it could ever be described.

“Incredible,” she replies tightly.

You think about it for a moment. You’re completely rock hard right now and would love to throw away the questions and fuck like rabbits, but you _are_ also enjoying them a lot.

“Want… to see how long we can keep going?” Your voice is as tight as Lisa’s. “See how many we can ask before one of us jumps the other?”

It sounds like a game almost, with the loser being the one who loses composure first.

Lisa nods.

“What’s the dirtiest thing… you can think of?” Her voice is quiet, she sounds like she is really struggling to not jump you.

There’s – well – one crazy dream that fits that. You nervously lick you lips for a moment as you think about the phrasing. There are a few things you change slightly as they’ll just make it hotter.

“It’s… here, in this room. I’m sitting on the bed like I am now… but I’m naked. You’re…” You pause, imagining the scene in detail. “You’re in a wedding dress. You look beautiful in it and we’re wearing matching rings.”

Lisa’s eyes light up.

“But we’re as old as we are right now, and you’re…” you nervously swallow. “.. pregnant. You look just _ridiculous_ beautiful. Like, I can’t find the words for how incredible you look.”

Lisa’s in shock again at your words.

“We’re fucking, and you look so happy with your dress bunched up around your hips. My beautiful pregnant wife _Lisa_.” The thought takes your breath away. “You’re telling me we’re going to make _lots_ of babies, and I know every one of them will be fucking beautiful, that we’ll make some incredible children together.”

You’re so turned on you almost start rutting into the air. Lisa looks at you in this mixture of shock, amazement, lust and desire. She wants it.

Then her face falls, a look of worry crossing it.

“Are you… worried about inbreeding?”

Your heart breaks: Lisa sounds like she’s about to cry, and not the happy kind.

“A bit,” you carefully reply. “I – I researched it.” You try to hide your worry with a not-so-casual shrug. “With no history of inbreeding – well, there’s not _no_ risk, but it’s not large, even between… siblings.”

It wasn’t a discussion you wanted to have, but it was _needed_.

“They don’t make it illegal for people with _really_ serious inheritable diseases to have kids. I mean, Huntington’s gives you 50/50 odds you kids will have it and it’s a horrific disease, but they don’t tell people with it to not have kids.”

It’s not a nice line of discussion and you hate it’s a mood-killer. You give her a sad smile as her eyes wet.

“The risk of our kids having birth defects is something like… _3%_ compared to 2% in the general population. It’s not… great, but…” you admit. “You’re smart and principled, Lisa. I-I like to think you’d have wanted genetic testing done on any baby you have, and this is no different. You’d want to know your kid – our kid – is healthy before it’s born.”

Lisa sniffles slightly before nodding.

“Would you like to see what I researched?”

When you’d figured this out, you’d gone ahead and looked this up. There’s not loads of data, no doubt because of the stigma prevents people from coming forward for studies. Still, there was some data out there. Inbreeding (say first cousins and closer) was _really_ bad if done over long timespans, with the risks compounding in each generation. But it really wasn’t very risky if done once… and really, you would not be encouraging you kids to go down this path. A path that will no doubt be difficult and turbulent.

Lisa nodded and you slipped off the bed. Offering a hand, she shakily gets up. You quickly slip an arm around her and pull her close though; you’re not sure she can stand.

“Want me to carry you?” you ask.

Lisa’s tear-streaked face lights up a bit.

“Bridal carry?”

There’s a weak smile on her face as she nods. You crouch down a bit before hooking your arm under her legs and then with a small yelp you cradle her. Looking down at her she looks safe and comforted and you know how you can make things right.


	4. A Day of Firsts

**Loving Lisa**

**Part Four:**

**A Day of Firsts**

“Feel better?”

Lisa’s in your lap, reading the studies you’d found. She gives you a nod, a small smile on her face. You feel relief.

“So, do you want kids?” you ask seriously.

Lisa takes a moment before answering.

“Yeah,” she says. She sounds satisfied. “You’re right, any baby I had would have been tested anyway.”

You nod along.

“We might be… a bit messed up doing this, but we want our kids happy and healthy.”

Lisa’s smile widens as she twists around to face you better.

“I’m sorry for making you cry,” you say honestly.

Lisa comes up a bit short at the apology.

“It’s okay,” she replies after a moment. “I’m glad you thought about it, Bart.”

She sits in thought for a moment.

“I… want this to work, and we need to know all of… this.” Lisa gestures at the computer. “So thank you for remembering and thank you for looking after me.”

There’s some shuffling as she swings her legs over you to sit in your lap. You shut down your computer and face the girl you loved. Hopefully the next serious discussion is easier.

“Are you on the pill?” you ask.

There’s a moment’s hesitation before Lisa shakes her head at you.

“No,” she replies sadly.

“When did you period end?”

Lisa blushes slightly at the intimate question. Before she nervously shuffles.

“Ten… eleven days ago?”

You give her a small smile.

“As much as I want to make love to the love of my life right now, thirteen _might_ be a bit young to make you a mother.”

Lisa’s smile is a bit strained. She can’t disagree, even if neither of us liked it.

“It will be…” Lisa gave an annoyed shrug. “It won’t be until after college we can have a baby, Bart.”

“Yeah,” you agree quietly. “Still, we do need to think birth control in the meantime.”

“Have you got… rubbers?” Lisa asks after a moment.

You shook your head. You might need to get some.

“How will mum react to you asking to go on the pill?”

Lisa gives you an awkward shrug.

“No idea.”

You think for a moment before deciding to shelve the issue.

“Let’s say… I decided to jump my gorgeous little sister. Would she like me to eat her out as promised?”

Lisa lights up again, her eyes sparkling and her cheek flushing.

“I think my horny little _fertile_ sister needs it.”

The word _fertile_ seems to have caught her as you sister nervously swallowed before giving you a nod.

“Maybe in here?” Lisa asks.

You glance at your room.

“I was kind of hoping in your room, sis,” you suggest hopefully.

Lisa Blinks at you in surprise for a moment before looking happy at the suggestion, but you’re not sure if the idea of her bedroom that did it or if you reminding her she’s your sister that did it.

“My room?” she asks.

She gets to her feet, not visibly shaking anymore. You can see a wet patch on her shorts though. She shuffles in embarrassment for a moment when she spots you staring hungrily before taking your hand and leading you out the door.

<^><^>

“Maybe we could find a beach instead of a pool,” you say.

Lisa smiles at your suggestion. You’re between her legs, your erection pressing against her crotch.

“I might not be as warm.”

You shrug.

“I think the physical activity will keep us warm though.”

She nervously nibbles on her lip as your hand runs down to the bottom of her t-shirt. You pause a moment, her eyes on you as you push it up. Her breasts look delicious as they come into view and you don’t hide you hunger.

“Don’t you dare apologize for them,” you say. “I don’t want my beautiful sister apologizing for her body. It hurts to hear you put yourself down like that.”

She looks at you in surprise for a moment before nodding.

Lisa puts her arms up over her head as you keep pushing her t-shirt up and over her head. You can feel your heart thumping away as you stare down at your nervously blushing sister, then your lips find hers again. She groans into your mouth as you grind your erection into her. The dry hump through your clothes is painfully rough on your sensitive cock but you can’t help yourself.

By the time your lips break apart Lisa looks dazed, but she still makes it easier for you as you pull her bikini shorts off her, her face flushed as she nervously bites her lip.

All you can see a small patch of blond curls, Lisa having pressed her thighs together, her legs bent and knees up above the bed. You want to dive right in, so you reach out the push them apart.

“Wait!” says Lisa suddenly.

Your eyes meet hers.

“Can I… can I see yours?” she asks smally.

You give her a smile before pulling your t-shirt over your head. You watch Lisa’s reaction for a moment before she rolls on side, closer to the foot of her bed. Then you slowly push your swim trunks down. You can feel the strain on your cock before it springs free, erect. Lisa’s eyes are wide, stuck on the member.

“It’s… big,” she says quietly.

It’s not huge, but you know that to someone who’s never seen one before it probably _looks_ big. It will get bigger over the next few years as well.

“Don’t worry, it will fit inside you,” you assure her.

“I hope.” Lisa’s voice is a whisper, her eyes still fixed on it.

You step closer before sitting on the edge of the bed, a hand reaching out and laying on Lisa’s hip.

“You ready, sis?”

You’re not sure if Lisa entirely likes it, but you know you do enjoy acknowledging your relationship.

Lisa looks nervous but she nods anyway.

“I’m ready, Bart.”

There’s a quick glance at Lisa’s current position before you figure out how things need to be rearranged.

“Move your bum to the edge of the bed for me, Lis.”

Lisa looks down at the edge of the bed for a moment before doing exactly that, lying on her and shuffling down slightly. Her thighs are still firmly pressed together though and her knees are up, her heels resting on the very edge.

You place a hand on her stomach and your eye greedily trail down from her face, over her breasts, her stomach and down to her small patch of blond pubes.

“Spread your legs for me, Lis.”

You try to give her a confident smile. She responds with a shaking nod before parting them. You can feel your own nerves and know your hand would shake if it wasn’t on Lisa’s stomach.

Your hand start moving downward, and you watch Lisa’s face. Her eyes are on your hand. You can feel her pubes first and take a moment to run your fingers through them. They feel slightly damp and then you press on.

You feel her clit with your middle finger next. Lisa draws in a breath of air as your finger brushes over it. You move past though, your finger curling into the warm wet entrance of her pussy. Lisa whines.

“I love how wet I’ve been able to make you Lisa.”

You draw your hand back, carrying some of Lisa’s slickness with you. It coats Lisa’s firm clit. Lisa whines as you give it a good rub.

“I love that you find me so attractive that I can make you drip like this,” you say, leaning in.

As you move over her, Lisa’s eyes break off your hand and meet yours. You kiss her as you push your fingers down again and curl into her dripping core. She moans into your mouth.

“God, you’re so fucking beautiful,” you tell her, your lips breaking for a moment before you dive back in.

You can feel Lisa move her hips to your rubs. Then, feeling confident, you push your middle finger into her entrance.

“How’s that, sis?”

Lisa’s hip movements are forcing your finger in and out of her to the first joint. She gasps.

“Tight,” she manages to get out.

You smile and add a bit more pressure, your finger sinking slowly deeper. Lisa draws a shuddering breath. You give her a soft kiss before withdrawing to watch her flushed face.

“God, I really wish I could put a baby into you right now,” you say, as you finger sinks to the knuckle.

Lisa gives you a whine, her hips thrusting slightly, fucking your finger.

“I-I wish you would,” she says with a gasp. “I-I wish you wouldn’t b-be so responsible.”

You give her an experimental single fuck with your finger and she gasps.

“I want to be able to help you, Lisa. I want to be their to help you raise our kids.”

You twist your hand slightly, your thumb finding Lisa’s clit, and you start thrusting your finger into her.

“I –” Lisa gasps. “– know.”

Her hands go around your neck and she pulls you into a kiss. You thrust you finger into her more urgently. Your lips break apart.

“I – I love you.” Lisa gasps again. “I love you, B-Bart.”

“I’m going to marry you, Lisa. I’m going to marry my incredible little sister and put as many babies in her as she wants.”

Lisa whines and her thighs start closing around your wrist. Propped up with your other arm, you watch her face close. She’s just making a series of gasps and then she cums with a beautiful needy whine.

Unable to hold of you tenderly kiss her, your finger fucking slowing. This isn’t what you had planned but it’s amazing all the same.

<^><^>

You cradle Lisa in your lap as she comes down, a sappy smile on her face. Your dick is only inches from her and her eyes are on it.

“Thank you, Bart,” she says after a few minutes.

“I was going to eat you out but I got distracted,” you admit.

Lisa’s eyes jump to yours.

“Can we… wait?” she asks tentatively.

“Anything you want, sis.”

There’s a moment as her eyes snap back to your dick and a hand reaches out for it. But Lisa pauses.

“ _Anything,_ Lis,” you reassure her.

Lisa’s fingers wrap around it and after a moment she gives it an experimental jerk. You return her ministrations with a gasp. After everything that has happened you know it won’t take long for you to cum.

“Oh, yeah,” you groan out encouragingly.

Lisa keeps stroking but then she slows before stopping completely, her hand completely retracting your foreskin. She’s looking at it, nibbling on her lip again. You have some idea what’s going through her mind.

“Want me to sit on the edge of the bed?” you ask.

Lisa’s eyes jump up to yours, a greater blush on her face. You give her an encouraging smile.

“Should I sit on the floor?” Lisa asks tentatively.

You nod.

“Yeah, otherwise you’ll be hunched over or lying flat.” You’re pretty sure the movement required would be more tiring lying down.

Lisa slips out of you lap and you shuffle to the edge of your sister’s bed. Lisa follows after a moment’s hesitation before standing before you. It’s the first time she’s stood naked in front of you since this began and your eyes sweep over her. Her cute face, her kissable lips, her cute breasts, her trim waist and budding hips.

“You really are beautiful, Lisa.”

She gives you a weak smile and then, using your knee for support, kneels in front of you.

Lisa hasn’t said a word about it, but you’re sure she wants to give you a blowjob. She reaches out and gives your cock a few more strokes before shuffling a bit closer.

“What – um – should I do?” she asks unsurely.

You reach out and push a few fingers through her short hair.

“What did you want to do, again?” you ask cheekily.

Lisa looks away in embarrassment for a moment.

“I –” Lisa’s voice drops to a whisper. “I want to suck y-your cock.”

You try to smile reassuringly.

“Just keep stroking the shaft,” you suggest, trying to think of what the best way to do it might be. “Use your mouth and tongue on the head. Like the underside of the head and the sort of ridge around the head.”

You’re sure there’s more, but you know you’re so turned on right now that the specific don’t matter. You can figure it out another day with Lisa.

Lisa stares at you a moment before turning to your cock. She gives another few strokes of the shaft, a thoughtful look on her face before opening her mouth and enveloping the head of your cock. You gasp as she sucks and then gasp again as she runs her tongue around it.

“T-that it, Lisa,” you say with a shuddering breath.

Your other hand reaches out to joint the first in running your finger’s through Lisa’s hair, your eyes on Lisa’s face as she sucks and strokes your cock. Then it starts, just a little at first but soon Lisa is bobbing her head to the strokes, taking more of your cock into her mouth, her petite breasts jiggling with each movement.

“God, I love you sis!”

Lisa’s face is red as he eyes glance up at yours. You think you saw a glimmer of amazement in her eyes for a moment before she returns to concentrating your pleasuring you. It hasn’t been long, but after today’s rollercoaster you can tell you’re close to cumming. You help Lisa along as your hips start giving small rolling thrusts.

“I’m close.”

There’s another amazed glace at you before Lisa picks up the pace.

You can feel the tension in your balls and know it’s close. You groan.

“Here it comes,” you say, your voice strained. “Don’t stop!”

The first spasm hits you, forcing your cum through your dick. Lisa falters a moment – her mouth opening slightly, but she keeps stroking your cock as another jet of cum spurts into her mouth. She looks like she’s going to pull back and you slacken your hands, but she stays, before the third spurt enters her mouth. Lisa finally pulls away, her hand strokes loosening. You can see her mouth is partially closed but a small amount of cum is dripping over her lip.

Lisa’s eyes look up at you causing her to miss the fourth spurt that splatters on her face. The surprise causes some more cum to dribble out of her mouth and she lets go of your cock. Knowing you have more in there you take over and give a few more strokes, getting another few spurts over Lisa’s face and chest as the stuff on her face starts dripping down onto her breasts.

It’s fucking beautiful.

Lisa wipes off some cum near her eye before giving a small gulp, swallowing the cum in her mouth. She looks like a mixture of amazed, shocked and embarrassed.

“That was incredible Lisa,” you say proudly.

Lisa blinks at you a moment.

“Thanks,” she says quietly.

Lisa take a moment to wipe off some of the cum on her with her hands.

“There’s so much,” she says. “What am I supposed to do with it?”

Lisa is staring at her cum covered hands for a few seconds before she reaches downward. She’s about to cup her pussy in her cum covered hand before she pauses. You raise an eyebrow inquisitively at her as her eyes slowly trail back up to you, an embarrassed look on her face.

“Maybe… that’s not a good idea,” Lisa mutters carefully.

“While I’d like to put a baby in my little sister by cumming deep inside her, watching her finger herself with my cum on her fingers would also be pretty hot.”

There’s a small shake in Lisa’s hand as you say that before she nervously gulps.

You incline your head slightly.

“Did it taste good?” you ask.

Lisa hesitates before replying.

“I don’t know.”

You give her a small encouraging smile and then Lisa lifts the hand to her mouth. She carefully licks a finger, a look of thought on her face.

“It’s… salty… and strong, I guess?”

There’s amusement on your face as she licks the other fingers before wiping more cum off her breasts. But as you glance out the window you realize how low the sun is getting.

“Where’s your phone, Lis?”

Lisa looks up from her hands at your question.

“Hmm?”

You spot it on her bedside table and get up to check the time.

“I _want_ to eat you out, but we need to get cleaned up before mom gets back.”

Lisa looks at you in shock.

“How soon?” she asks worriedly.

You raise a placating hand.

“Relax, we’ve got like forty minutes.”

Lisa looks relieved.

“Want to have a shower together?”

Lisa’s face lights up.


	5. The Wilderness Awaits

**Loving Lisa**

**Part Five:** **The Wilderness Awaits**

The shower is sweet and just filled with kisses and groping before you reluctantly get dressed and head downstairs. When mom gets home you do your best to not look like you had been one hesitation away from impregnation your sister as Maggie happily tells Lisa about her day.

Over the next few days Lisa is… touchy-feely. It’s a nice change, of quick kisses at secluded moments of the day and some cuddling in front of the TV. But you don’t get the opportunity to go any further. You do manage to grab some condoms from the Kwik-E-Mart though, Apu asking you who the lucky lady is which you manage to brush off with only some embarrassment.

“So, did you ask mom about the pill?” you ask.

Lisa sighed in your arms.

Dad’s already at work and mom was talking a six-year-old Maggie to a playdate leaving you with a free twenty or so minutes. Unfortunately, the early hour and lack of forenotice just meant you were standing behind Lisa in the bathroom as she brushed her teeth, your arms around her instead of doing something else. You were half-tempted to slip your hands under her shirt and feel her breasts, but you might get carried away.

“Mom did that thing – _you know_ – where she says okay, _but wait_ ,” Lisa explains. “She said I shouldn’t _need_ to go on the pill and that I can ask her again in a few months.”

You grimace.

“Yeah, I get you. Lame.”

Lisa nods and goes back to brushing her teeth.

“Are there other options?” you ask as she finishes.

Lisa meets your eyes in the mirror a look of irritation on her face.

“No, you’ve got to have parental permission in this state,” she says bitterly.

“Christ, that’s dumb.”

Lisa snorted in agreement.

Lisa pauses though, a look of worry on her face.

“What do you think of… virginities?” she asks, almost looking disappointed in herself.

You’re not sure where the discussion is going.

“Like, losing them?”

Lisa fidgets in your arms.

“Like… hymens and bleeding your first time.”

There’s a small amount of distaste on your face.

“Pretty shitty for the girl really.” That’s true, a hymen just exists to ruin a first time. You’re not sure why so many people are fascinated by the damn things. “Why, you worried you don’t have one?”

Lisa looks a little bit surprised.

“Um – no, it’s just… I – um – broke mine,” she says nervously.

You can almost see where this is going.

“Like, recently?”

Lisa’s lips are pressed thin and her eyes are off somewhere else.

“… last night.”

You smile and try not to laugh before that fails and you’re laughing out loud.

“Really?” you ask gleefully.

Lisa nodded with a slight amount of bewilderment.

You kiss her cheek before hungrily whispering into her ear.

“I rather like the idea that my mere presence can turn my little sister on _that_ much.”

Lisa blushes furiously before a sappy smile forms on her face.

“Don’t be embarrassed by it, Lisa. I _really_ do like it that you find me attractive, and I like seeing and hearing the proof. I like knowing I can make you a dripping hot mess.”

There are a few moments of comfortable silence before Lisa turns around and kisses you. The addition of toothpaste is interesting.

“Kids?” Mom calls out. “I’m back.”

You both quietly sigh before separating.

<^><^>

“Mom, dad?” Lisa asks over dinner a few days later.

You’re not sure what she wants to ask so you glance at Lisa inquisitively.

“Yes, sweetie?” dad asks.

Lisa glances at you a moment.

“Bart and I were thinking,” she starts. It’s odd because you don’t remember discussing anything that needed mom and dad looped in. “Can we go camping? Bart and I, that is?”

You try to hide the surprise on your face. You had discussed this, but not recently.

“Camping?” Dad says positively.

“Camping, where?” Mom presses for details.

“The national park.”

It’s probably an hour’s walk from home, the closest park to Springfield. Though you might be able to wrangle a lift from mom or dad.

“You sure you don’t want your old man coming with you?” dad asks.

“We were going to do a lot of hiking, dad,” you quickly add.

Dad deflates a bit. He’s… not really built for it.

“What else are you going to be doing?” Mom asks with a small amount of suspicion.

A moment of panic surges through you before you get it under control; mom _clearly_ is talking about your predisposition for fireworks, BB guns and things that go bang.

“I wanted to take some photos,” Lisa says. You can tell she’s deflecting.

There’s a glance at Lisa as you think of a legitimate reason for going.

“Eh, I just wanted to get out of the house,” you say with a casual shrug. “And I know you wouldn’t want Lisa going alone, so it works.”

“We’ll have our phones,” Lisa quickly adds.

“Yeah, you can get reception in the entire park now.”

You didn’t actually _know_ that, but you probably got reception in most of it.

“Sounds like a good excuse to get you two out of the house,” dad says, glancing at mom.

You’re internally jumping with joy. It’s in the bag now.

“It will be a good thing to get Bart out of the house and away from video games,” says Lisa.

Mom certainly complains about _that_ enough. It’s never directed at Lisa, even though she plays them as well and almost as much.

Mom grumbles.

“Fine, but I want to see you two pack properly.”

“Thanks mom!” you both say.

“And I mean it,” she continues. “I want to see you two pack the right equipment and the right clothes.”

“Yes, mom,” you agree.

“And how long?” she asks. “It can’t be for too long.”

You glance at Lisa and mouth _three_. She gives you the tiniest nod.

“Three nights?”

“Hmm.”

Mom looks skeptical.

“You can go for two,” she says after a moment.

You shrug. Two or three doesn’t matter that much, and you can probably wrangle another night over the phone. You could always claim you hadn’t watched the time and if you started packing now it would be dark by the time you got home. Tripping and breaking something in the dark and all that.

“Alright!” says Lisa enthusiastically.

“Can I come too?” Maggie asks.

Your mind races for something to keep your baby sister at home, ideally without too many tears. You can see mom doing the same thing. Lisa saves the day though.

“We’re going to be doing _lots_ of walking,” says Lisa kindly. “ _And_ we’ll have to carry loads of stuff.”

“I can do that!” Maggie says with enthusiasm.

Everyone at the table is very skeptical of that.

“How about you try carrying my pack when we’re getting ready?” Lisa suggests.

You can see mom following where Lisa is going.

“Yes,” mom says. “You can’t go camping unless you can carry _all_ the equipment you need to protect yourself from the weather.”

“Yeah, there’s loads of stuff,” you say in agreement.

That problem is neatly solved.

<^><^>

Lisa and you pack your bags in the living room that night with the plan to leave tomorrow morning. You’ve got everything laid out to sooth mom’s worry before packing it up. _Most_ of it anyway. The small number of fireworks would go in right before you leave. You didn’t have too many, just a few simple things. You’re not even sure you’ll use them, because Lisa does actually want to take some wildlife photos. You’ll also swap some things out when mom’s not looking, things that are not incriminating but hard to explain.

There is one other thing…

“Hey, Lis!” you say, spotting Lisa in the hallway.

You point at your bedroom and trust Lisa to follow. Dad’s working and mom is downstairs, likely nosing through your camping equipment so you’re not worried about being found. Lisa looks like she thinks you’re going to take a moment to make out but instead you go to your draw and pull something out. You hold them up for her.

“Oh.”

Lisa blushes with that small sappy smile you’ve figured is her response to good but embarrassing things.

You’ve still carrying the connected packages of rubbers as you step up to her, placing your hands on her hips.

“So, are you up for it, Lisa?”

Her eyes are bright looking up at you.

“Yes, Bart.”

You kiss her tenderly in response.

<^><^>

Unsurprisingly, Maggie couldn’t carry the pack, and with a few tears she was left behind in mom’s care. Not that mom would have left her with us on a camping trip anyway. At home for the night? Sure, but not camping.

The packs are heavy though, and you’re glad the park isn’t huge or too far away, so the walk is only an hour to the park and maybe another thirty in deep. Mom refused to drop you off though; you sure it was for Maggie’s sake.

“Bart, can I ask a question?” Lisa asks as you hit actual forest.

You pause, and figuring no one will see you you hold a hand out for Lisa. She takes it and you walk close.

“You don’t need permission to ask me anything, Lisa,” you say. “I pretty much asked you to marry me.”

She gives you a smile and nods.

“Doesn’t that make you my fiancé?”

Lisa blushes and that cute smile adorns her face. You’re walking backwards to properly enjoy its sight.

“Lisa Simpson, my beautiful little sister and fiancé.”

Lisa’s eyes light up, but there’s a touch of nervousness.

“That’s… what I wanted to ask,” she says.

You slow, slightly worried.

“How about we stop for a snack?”

So you do and drop your pack on the ground, taking a seat on it. You worry is relieved slightly when Lisa drops her own pack near you and sits close. But the worry is still there.

“Bart…” Lisa says, clearly still composing what she wants to say. “… why do you bring up that… I’m your sister?”

You try to hide your cringe; you didn’t realize it had made Lisa uncomfortable.

“Well,” you begin, an awkward hand scratching your head. “I kind of like the naughtiness of it.”

The answer doesn’t answer everything though and Lisa can tell.

“I…” you pause again, figuring out how to say it without wrongly implying _that_. “I’m glad I fell in love with you Lisa, but part of me wishes our… luck had been different, that we’d not been siblings.”

Your explanation doesn’t make much sense to Lisa, and you can tell.

“But that is the case, and I guess I’m angry no one else will let me love you. Like, everyone will be against us. So, I’m kind of enjoying the fact this _is_ taboo and I like the fact you’re my sister too. It’s… strangely perfect; that the girl I love is also my best friend and sister. I enjoyed it.”

The explanation is rambling, and you awkwardly break eye contact.

“Oh.”

Lisa looks like she needs a moment to process.

“If it bothers you, I’ll stop, Lisa.”

Maybe it’s the worry on your face that prompts it, but Lisa rests her head on your shoulder.

“It _is_ a bit thrilling,” she agrees a few moments later. “It’s… just still a bit shocking.”

“Want me to stop?” you ask.

You can feel Lisa’s head shake against your shoulder.

“No, it’s okay. I’ll get past the shock.” Her head lifts off your shoulder and you turn to see her looking back at you. “I want to marry my big brother.”

<^><^>

After a few kisses you get back on the trail again.

“So, I guess we should avoid the normal camping spots?” you ask.

“Yeah,” Lisa agrees.

“You know that means no toilets, right?”

Lisa catches your eyes before shrugging.

“Yeah, but it’s better than constantly worrying if someone is watching us or figuring us out.”

You nod.

You do agree that you should still be within ten or fifteen minutes’ walk of a designated camping spot though, just in case. You pick somewhere a good distance off the trail though.

“So, do you want to go do things, or should we set up camp?”

Lisa nervously nibbles on her lip clearly in thought.

“I don’t want to wait.”

You’re pretty sure what she’s referring too.

“Not having a tent up won’t stop us, will it?”

You shake your head, there’s no chance.

“So, tent up, and then I make love to my fiancé?”

Lisa smiles and nods.

You were very conscious of the fact that _yes_ you did want the tent built as fast as possible, but you also didn’t want it uncomfortable or to fall down on top of you and your sister. If Lisa and yourself didn’t like camping, this wouldn’t be perfect. But thankfully you both did.

Lisa was lying on the uninflated air mattress with her eyes on you as you put together the pump. Her hiking boots were off and by the side of the tent, and she casually swung her feet in the air, her head propped up in her hands.

“You know, you might be a bit _too_ sweaty before we even start if you do that.”

You look up from the pump at her for a moment. There’s a faint blush on her face and you’re pretty sure you catch her drift.

“Yeah,” you agree, going along with it. “It would be a shame to get my clothes all sweaty.”

You had both showered just before leaving and the weather was pleasant, not hot, so you’re sure neither of you stink. It wouldn’t have stopped you though.

“Mmm-hmm,” Lisa hummed in agreement. “Best you take it all off, Bart.”

You’re half tempted to make a show of it, to drag it out, but you’re sure you don’t want to delay any further, so you pull it off fast. As you stand there naked, you’re glad to see a hungry look in Lisa’s eyes. She regretfully has to get off the air mattress though as you pump it up, Lisa stepping out of the tent.

Your eyes follow her as she grabs goes to the bags, pulling out a bedsheet and a spare blanket Lisa had grabbed from the house. A set of sleeping bags would normally be more practical, but for tonight and tomorrow night, this was better. She then leaves them next to the airbed before taking a seat on one of the packs to watch you work.

Your cock was already partially erect, but it doesn’t take long thinking about peeling Lisa’s tight shorts and t-shirt off her to get you going.

<^><^>

Lisa is lying there for you. You knew this was coming but seeing Lisa waiting for you on top of the bed was the actual realization that you were about to make love to your sister. Lisa seems to be in the same boat, her blush steadily having intensified as she laid the sheets out.

You could see her red face staring back at you with anticipation as you sat naked between her legs.

“Bottom first?” you ask as you reach for the button of her shorts.

Lisa raises her bum as you pull them down, revealing her soaked underwear. It was a cute set of stripped colored boyshorts, the large wet patch standing out down the middle.

“You know, I keep promising to eat you out, little sister, but things keep coming up.”

Lisa squirms at your words.

“No,” Lisa replies. She sounds frustrated. “I don’t want to wait anymore.”

It’s a fair comment and you’re not sure you could wait either.

Sitting over her, you push her t-shirt up revealing a matching bra. You can’t reach that far so Lisa pulls the t-shirt off herself.

Next is her bra. You don’t see anything that could get it off her while lying on her back. After a moment’s thought you gab both of her hands and lift her upright. Lisa yelps as she lands in your lap and then laughs. It lasts a moment before you kiss her, your hands working the bra’s hooks. When you pull back from the kiss, Lisa helps you get her arms though the traps, leaving her braless.

You gaze over her hungrily before diving into her breasts, your lips latching on. Lisa gasps and then you immediately add to the pleasure my slipping your hand down the front of her underwear and running your fingers though her soaked folds. Lisa whines into your mouth before pulling away.

“Just fuck me,” Lisa says desperately.

You lay her back on the bed and pull off her underwear, leaving her soaked pussy visible and needy.

“Where are the condoms?” you ask.

Lisa hesitantly points at the line of plastic packets sticking out from under the bed. You reach for them.

“I… shouldn’t be fertile right now,” she said, her voice tinged with hope.

You pause. _Should_ being the operative word. You can’t deny you want to do it raw though, not only would it feel better, that tiny pregnancy risk thrilled you.

“Lisa,” you say hesitantly.

“Just today,” she says, her voice laced with desperation. “Just our first.”

Your will lasts a second before you relent. You nod.

“I _hope_ I’m wrong though.”

Your heart suddenly feels like it’s in your threat.

“I hope so too, Lisa.”

Lisa’s eyes sparkle.

Moving forwards between her legs, you can feel the tip of your cock brush her pussy before leaning down and kissing her. You only kiss for a few seconds before getting up and pushing your cock through her wet folds. She’s wonderful slick and moans as your cock parts her before slipping up and over her clit. You want to savor it, but every other instinct is telling you to bury yourself in your sister’s waiting pussy.

“I love you, Bart.”

“I love you too,” you tell her as you push.

Lisa’s breath hitches as you take her hand and shift slightly for more leverage. Then you pull out a fraction before thrusting in deeper.

“Bart!” Lisa says, her breath hitching.

She looks fucking beautiful.

You withdraw some more and thrust in again, sinking deeper. Lisa’s pussy is wonderfully warm and soft, yet tight around your cock.

Leaning over Lisa you pull out again before thrusting again, this time to the hilt. Lisa makes a cross between a gasp and a whine.

“How’s that, sis?” you ask her.

Lisa takes several deep breaths before answering.

“It feels good,” she says, a dazed look on her face.

You lean down to kiss her and after a few moments her hand slips from yours she wraps her arms around you. You can’t wait, so you give your sister her first deep thrust. Lisa Gasps through your kiss.

Another thrust and another gasp and you decide you want to hear Lisa make those sounds. Your mouths separate and you stare at Lisa’s face only inches away. You thrust again.

The sound is almost like a cross between a gasp and a hiccup. A pride flows through you at the proof that you can make Lisa feel this way. You’re not sure you’ll last long though.

“Tell me –” you grunt “– _tell me_ Lisa, the baby names you picked out.”

Lisa makes a beautiful whine.

“Ah! I w-want – ah! – _Zia_ for – ah! – o-our daughter.”

Lisa closes her eyes a moment as she gasps. You keep thrusting.

“Max! – ah! – Max for a boy.

You kiss Lisa again.

“Zia and Max then!” You grunt. “I’m close Lisa!” Another grunt. “I-I’ve got a big load of baby batter for you.”

Another whine from Lisa.

“I-I love you Bart!” Lisa manages to gasp out.

You can feel Lisa’s legs wrap around you as you pick up the pace.

“Here in comes, Lisa!”

At this point the only sounds your sister can make is a long whine, the tone changing slightly, timed to each thrust.

As you feel your balls contract you give Lisa one last thrust before pushing as deep as you can go. Then the incredible agonizing feeling of your cock swelling before the first spurt of baby batter spurts into the girl you want to marry.

There’s a small not-quite-thrust as your cock swells again, giving Lisa another load of baby-making seed before your lips crash into each other.


	6. Like They Did Before Electricity

**Loving Lisa**

**Part Six:** **Like They Did Before Electricity**

It’s easily another five minutes before Lisa speaks.

You’re spooning her from behind, your arms around her stomach.

“That was incredible,” she says quietly.

“You were incredible,” you reply.

You kiss her shoulder blade, it being the closest kissable thing you can reach while spooning Lisa.

“I – I know that was just playing about, but… I really do hope you just made me pregnant,” she says.

You take a moment to compose your thoughts.

“Yeah, I hope so to,” you admit.

You can’t deny that.

“You’re going to look so beautiful pregnant.”

There’s another comfortable silence as you hug Lisa tighter.

“What do you want to do for college?” Lisa asks.

There’s that tinge of worry there again, so you take Lisa’s hand.

“I don’t know…” you admit. “I don’t want to leave until you graduate high-school. I definitely want to go to the same college as you, too.”

“If…” Lisa pauses for a moment, clearly in thought. “If we have a baby before college or during college, what do you think we should do?”

You have an idea where Lisa is going here and can see why she’s hesitant to suggest it. It’s in a way the antipathy of Lisa.

“Help you in any way I can,” you reply honestly. “I’ll look after the kids so you can go to college.”

There’s a fraction of a sad slump in Lisa at the words.

“I don’t want to stop you from going to college, Bart.”

You give her a reassuring squeeze and another shoulder kiss.

“It’s fine, you’re going way further than me, Lisa. I don’t want to see you flounder because of our kids.”

The worry is still there.

“I’ll be the stay-at-home dad, while you can be the incredible college student I know you will be.”

There’s a moment before Lisa rolls over to face you. The worry is clearly on her face.

“ _Really_ ,” you emphasize before giving her a soft short kiss.

Maybe see the self-assurance on your face does it, but Lisa does relax a bit.

“I can do college when you’ve graduated and the kids are older.”

It’s a bit strange to say _kids_ with such certainly, but it makes you feel warm and happy inside.

Lisa gives you a small warm smile before pulling you into a hug, her head nuzzling into your chest.

“Thank you, Bart.”

You give Lisa a kiss on the forehead.

“Love is about sometimes make little sacrifices so we can both be happy. There isn’t much I wouldn’t do to give you the kids you want.”

Lisa’s face is wet when she looks up at you, but there’s a wide smile on her face.

“When did you get so wise?”

You tenderly smile back.

“When I realized I had to work hard to have you,” you reply. “I want this to work and that means I can’t slack off.”

Her smile is a bit weak.

“I feel like I should be doing more,” she says.

You shake your head.

“Don’t worry about it, Lisa. Just focus on school and I’ll handle the rest.”

“Do you worry about school?” she asks worriedly. “You’re smart, Bart. I don’t want you ruining that for my sake.”

You think for a moment before shaking your head again.

“Nah,” you say casually. “I haven’t got a fraction of the work ethic you’ve got, Lisa. I can’t sit and study like you can. You’ll go way further than me.”

She still seems uncertain about it, but it something you can work on.

“As far as everyone else is concerned, I’m the big brother who just wants to help my genius little sister out.” You smile and don’t show any worry about it. “I’ll help with our baby, do the chores and help you with anything else so you can get to college and do well there. _I know_ you will do you well there.”

Lisa nods as you think about what you said.

“Do you want a baby before college?” you ask.

Lisa rolls her eyes a fraction.

“Yes,” she says obviously, a nervous, embarrassed and hopeful smile on her face.

To be fair, it is a bit of a dumb question.

“If you want,” you say carefully. “We could have a baby when you’re sixteen. I’ll have finished high-school and I can _tragically_ –” you roll your eyes dramatically “– delay college to help you raise the baby while you’re finishing high-school.”

Lisa lights up, she looks beautifully hopeful. She cuddles up to you a bit more, nibbling on her lip in thought.

“My birthday’s in May and we’d finish school at the start of June…” she lists. “So we’d… make our baby in… late August or early September.”

“For a baby right at the start of summer?”

Lisa nods.

“We’ll have to explain _how_ you got pregnant though.”

Lisa nods again.

“Yeah, some reason for why the dad’s gone and my wonderful big brother is here to help.”

You make a small laugh.

“Yeah.”

“Obviously you don’t know to guy’s name,” you suggest.

“Yeah, and he’s from out of town.”

“No one knows who he is.”

“Yep,” Lisa agrees. “He seemed nice, but I’m not sure where he went and don’t have anything to contact him with.”

“And big brother Bart loves me so much he’s here to help me all along the way.”

You smile for several seconds than another thought crosses your mind. You can’t hide the frown.

“Bart?” Lisa asks with concern.

“Oh,” you say, composing your words. “I’m… just a bit sad I won’t be able to tell anyone I’m the father… _really_ , I hate that I can’t shout to the world I want to marry Lisa Simpson as well, but…”

You shrug awkwardly. There’s not much of a solution to this.

Lisa smiles sadly at you before giving you a comforting squeeze.

“I know,” she says with a sigh.

“Yeah, I’ve already accepted it. It doesn’t change what I want to do.” You try to sound reassuring.

Lisa’s smile is a bit weak.

“Do you think we’ll be able to hide this?” she asks.

You give the barest of shrugs.

“Long term... probably not,” you admit.

You think about it for a few more seconds.

“I don’t think we’ll be able to hide it from our kids…”

Lisa nods in agreement.

“Yeah, they’re going to see you looking after them and call you _daddy_.”

You can’t hide the smile.

“I know.”

“If…” Lisa pauses in thought. “If anyone asks, we can tell them it’s because you stepped up to help me and it’s just too difficult to explain to them that their _real_ dad ran off.”

You nod.

“Yeah, that might work.”

Your thoughts turned to your own parents.

“Mom and dad will figure it out eventually,” you say. “Us living together as you keep getting pregnant and the father’s ‘keep running off’?” You shake your head. “Mom will figure it out. Maybe not dad, but she will.”

Lisa looks worried.

“Do you think they’ll do anything about it?”

Distaste crosses your face as you think.

“Not… if it happens after we’ve left home,” you say. “Shit will hit the fan if they figure it out before you’re eighteen, but if it’s at college or after? No. I think we just have to prove our kids aren’t… _you know_ –” an uncomfortable look crosses your face “– inbreeding stereotypes. Mom will love her grandkids and…”

You pause again to think.

“I think if we’re older and our kids are healthy, mom won’t even mention it if she figures it out. She’ll go into denial. Dad too probably.”

“And everyone else?” Lisa asks.

“Are we staying in Springfield?”

Lisa shakes her head.

“I don’t really want to.”

“Me neither,” you agree.

Another shrug.

“Our kids call me dad and we’re a long way from Springfield, people will just assume we’re a couple.”

You laugh as a thought occurs to you.

“They’ll see one adult bedroom and the idea that we’re siblings won’t cross their minds.”

Lisa smiles.

“Mom and dad will ignore it.”

“Yeah,” you agree.

Going back to the original discussion.

“You’re certainly smart enough to have a baby at sixteen and still get top marks, Lisa,” you say surely. “I know it.”

Lisa blushes at the comment and you lean in closer.

“It’s why I fell in love with you.”

Lisa’s eye go wide for a moment before her blush intensifies.

“You’re pretty smart too, Bart,” Lisa whispers.

You shrug.

“Yeah, I guess, but it’s you who’s able to actually sit down and use it.”

You kiss her softly for a few moments to quell any dispute.

“This will probably work better for us. I’m… well, I’m not sure we’d actually hold out until after college. Actually planning a date – a date that works – is smarter. Better than falling pregnant in the middle of coursework or something.”

“It’s a good excuse for why you live with your sister, too,” she adds.

You nod.

“But, having a baby then won’t stop me from looking after you and holding your hand the whole way, I promise you that Lisa, but it’s still better to plan.”

Lisa’s eyes are wet again, her smile radiant.

“So, two and a bit years?” Lisa asks.

You nod.

All this talk of babies has gotten you hot and bother again, and you’re sure Lisa is the same. You kiss her and pull her close, letting her feel your erect cock between you. Soon you’re on round two.

<^><^>

You’re lying flat on your stomach in the bushes. Only a few feet in front of you was Lisa, her camera in hand.

“ _Just stay still_ ,” she quietly muttered as she waited for the photo opportunity.

Lisa was crouching and while you knew there was a deer out there she was trying to photograph, your eyes for the last few minutes had been on Lisa’s ass.

She _really_ did look good in those thigh shorts and they showed off her legs nicely too.

Your eyes look up at the sound of the shutter though. Lisa manages to get several photos.

“No! Don’t run off!” she exclaimed a bit too loudly.

Lisa dropped her camera onto its strap as you got up behind her. You tried not to laugh, but when she turned around she did look slightly peeved. It may have been your slightly too wide smile.

There’s a faction of second before she moves to a small embarrassed smile.

“I might have been too loud.”

You both start laughing, but your thoughts quickly turn back to Lisa.

“Have you ever thought about doing it in the forest?” you ask her.

Lisa’s cheek tinge pink.

“I’m… not sure it would be that comfortable.” Lisa’s eyes are on the plethora of sticks and stones that litter the forest floor.

“We don’t need to do it in the dirt,” you say, stepping closer, a hungry look on your face.

Lisa nervously nibbles her lip.

“What were you thinking?” she asks unsurely.

You give a quick glance at your surroundings, just in case there’s someone about before turning back to Lisa.

“Unbutton your shorts and turn around,” you say. “You’ll want to grab onto the tree.”

Lisa’s eyes meet yours. She squirms a moment before doing as ordered and then starts to push her shorts down.

“Nah, just up against the tree,” you say, stopping her.

Lisa looks over her shoulder at you as you step behind her and then tug her shorts down to her knees yourself, followed by her underwear. Her cute ass looks inviting as you under your jeans and push them down, freeing your firm cock.

“Ready, Lis?” you ask.

Lisa nods her red face over her shoulder as you probe her pussy with your cock. It doesn’t take you long to find it and lodge your cock in her. Lisa gasps as you push it in as far as you can, her soft tight pussy stretching around you.

It’s not as deep as you could go fucking your sister missionary style because of Lisa’s ass cheeks, but there’s something primal about making love to her in the woods from behind. You place your hands on her hips and try pushing deeper.

Perhaps unsatisfied by the depth, Lisa bends over more, pushing her ass out at you.

“That’s it, little sis, I’ve got that baby batter you need right here,” you tell her encouragingly.

Lisa whines as you start giving her slow, deep thrusts.

It’s far less frantic and you last far longer than your first time, or your second, or third. Three days of the hottest sex imaginable leaving Lisa beautifully sated with cum dripping out of her pussy was making you last a lot longer.

You did get some other things done… occasionally. But it was usually diverted by more sex. Your eyes are strangely focusing on Lisa’s left hand up against the tree. You tell yourself you’ll get her an engagement ring for those fingers of hers.

Turning back to Lisa you push her t-shirt up to expose her bra strap. You’ve got it unhooked it a second before sliding your hands underneath her to fondle her breasts.

“Ah! That’s it!” Lisa exclaims as you start squeezing her nipples to each thrust.

You keep going, inching closer to release. You can feel the sweat dripping off you and can see it run down Lisa’s back.

“I’m getting close Lisa,” you tell her.

“Yes! Yes! Yes!” Lisa starts saying.

Your hands still on her breasts you pull your sister up, hugging her to your chest before stepping closer to the tree so she can grab on. Lisa’s back is curled so she can still get the best angle as you thrust, but now she’s close enough to kiss. The angle isn’t right for her lips but you can still nibble on her ear and plant your lips on her cheek.

“Give me – give me a baby, Bart!”

You grunt and start thrusting more firmly, you can feel you’ll cum any second now.

“I’ve got it –” another grunt “– right here, Lisa!”

Lisa whines as you feel yourself swell before you push your cock as deep as you can into her. As spurt after spurt fills your sister, you desperately hope your child is beginning to grow inside her.

It’s a minute or two of you whispering soft words into Lisa’s ear before you pull your semi-erect cock out of her with a wet noise. Lisa’s legs are shaking and you enjoy the sight as you crouch down behind her.

Lisa pussy looks beautifully full, a dribble of white cum visible on her nether lips, before you regretfully pull her underwear up over it followed be her shorts. Your arms around her, you even zip them up and do up the button for her before dealing with your jeans. Her face is a wonderful sweaty mess as you kiss her.


	7. Plans Led Astray

**Loving Lisa**

**Part Seven:**

**Plans Led Astray**

It’s late and mom and dad are in bed as you scroll through page after page on your computer.

You probably need a lawyer to look things over to be certain, but there were some options here. None that were robust, but they’d give you and Lisa a marriage certificate. It would hold up as long as no one connected the dots. And if they did, it just invalidated the marriage, no punishment dished out.

It had been a few days since you got back from camping. You’d managed to find a moment to make love to Lisa in your own bed but didn’t get to enjoy sleeping by her side. Hopefully some opportunities would come up over the summer.

There was a knock at the door and you quickly closed the window on incest laws.

“Bart?”

Hearing Lisa’s voice you relaxed.

“Door’s open, sis.”

As she was here you figured you’d tell Lisa what you found and turned back to your computer, but then you saw Lisa’s face. She looked down.

“Lisa?” you asked, getting to your feet.

Lisa fell into your arms and you hugged her. She wasn’t crying but something did seem to be wrong.

After a few seconds you led her to your bed, taking a seat close to her.

“Lisa?” you ask again.

Lisa looks up from you.

“I got my period.”

You slump a bit. The cause of Lisa’s unhappiness obvious.

“Oh Lisa,” you said kindly, pulling her into another hug.

You cradle her for several minutes.

“I – I know I shouldn’t be sad about this,” she says quietly, her head on your chest.

“It’s okay to want something, Lis.”

Lisa nodded thickly in your arms.

“I-I wanted you to be pregnant too,” you admit.

You might have talked about it a lot during sex, but saying it here, while you were both levelheaded and not in some orgasmic afterglow was different.

Lisa’s eyes were wet when she looked up at you.

“I –” Lisa swallowed nervously. “I want you to make me pregnant. My n-next cycle, Bart.”

It felt like your heart stopped as Lisa said those words. You tried to form an objection.

“If-if we have our k-kids earlier… they’ll be older by the time we’re in college,” Lisa explains. “They’ll be four or five… maybe another who’s three or four. They’ll be – they’ll be old enough for daycare. You can go to college with me, and we’ll have our babies.”

You _know_ this is just an excuse from Lisa, an attempt to rationalize impregnating her in a few weeks, but you’re having trouble disagreeing. You _really_ want this, and you can feel your resistance weakening.

“You’ll be a mother at _thirteen_ , Lisa,” you say, trying to put some resistance up.

“I know.”

There’s not a hint of despair in her voice, and _you know_ she’ll look so beautiful.

Now you’re nervously chewing your lip.

“How many babies, Lisa?”

Lisa is bright at the question, a small smile on her lips.

“Two for now,” she says. “Maybe later we can have more.”

You slowly nod, the image of a pregnant Lisa still on your mind.

“How many do you want, Bart?”

You pause.

“I – I don’t know,” you admit. “Two for sure… I – uh – I can’t get the thought of you pregnant out of my head.”

Lisa blushes, a cute smile on her face.

“I kind of want you always pregnant… but… maybe twenty kids is too much.”

Lisa giggles.

“Maybe,” she replies.

You both fall silent, a hopeful look on Lisa’s face.

“Will you make me a mother, Bart?” Lisa asks carefully.

Against everything in your head telling you it’s a silly, ridiculous idea, you nod.

“I will, Lisa.”

You softly kiss Lisa for what seems like ages before you remember the computer.

“I found some stuff,” you say.

Curious, Lisa follows you to the computer, taking a seat on your lap.

“So, New Jersey and Rhode Island don’t have a law against incest between adults. So, if we have to we can go there.”

Lisa nods, her eyes reading down the screen.

“They wouldn’t accept us getting married, but there’s no punishment, the marriage is just voided. So, if we can get a marriage certificate signed and no one realizes we’re siblings, it will hold up. I don’t know for how long, but as I understand it records aren’t very well checked in America, so maybe a long time.”

Lisa looks even brighter as she swings around to face you.

“So, Lisa Simpson, will you marry me?”

Lisa answers with a kiss.

<^><^>

Lisa shakes her head a few days later.

“No, let’s just get wedding rings,” she says.

You’ve both been browsing through the selection online. You were both pretty sure that a fifteen- and thirteen-year-old walking into a jeweler looking for rings would raise far too many eyebrows, particularly in Springfield where everyone knew each other.

You shrugged. Engagement rings were a bit flashy.

“Works for me,” you reply.

You click through a few bookmarks of things that caught your eye.

“Have you found anything?” you ask.

Lisa turns her laptop to you.

“A couple.”

Money wasn’t an issue and you had laughed a bit when you saw the look on Lisa’s face at seeing how much money you’d made through options trading and cryptocurrency. Neither were safe investments, except that you had sort-of future knowledge guiding you. You’d given Lisa access on the spot.

“You’re not sure though, are you?” you ask, seeing uncertainty on Lisa’s face.

Lisa gives a small shake of her head.

“Maybe something custom then?”

Lisa looks at you curiously at the suggestion.

“Like, we draw up a design for what we want to give each other, and send it off to a jeweler to make?”

Lisa nodding at the idea.

“That might work.”

You would rarely get to wear the rings, but you might be able to hide their true meaning if they were on necklaces or something. At least until you were out of Springfield.

So you both drew up some sketches and sent them off. The jeweler would give process reports and you could ask for changes. They weren’t complicated, but they did have some uniqueness to them, and it meant something.


	8. Fertile Fields

**Loving Lisa**

**Part Eight:**

**Fertile Fields**

“You all set, Maggie?” Mom asked.

Maggie nodded.

“Yep!” she said enthusiastically, a bag of sleepover stuff on her back.

You and Lisa had thought you’d have to come up with something, but fortune smiled upon you. Maggie was at a sleepover and mom and dad were taking the opportunity to spend the night away at a bed and breakfast. You and Lisa had the night alone, right in the middle of Lisa’s fertile window.

Mom turned to you and Lisa.

“I’ve got plenty of groceries in the fridge so you shouldn’t need to order takeaway,” she said.

“Yes, mom,” you reply.

The comment is mostly directed at you.

“Your father and I will be back tomorrow afternoon,” she continues. “I expect the house to be spick and span when I get back. I will know if you’ve held a party, if only from Mr Flanders.”

You had never actually done that before.

“Oh, hey, that’s not a bad idea, mom.”

Mom frowns, scrutinizing you for a few seconds before deciding you had said it in jest.

“We’ll be fine, mom,” Lisa reassured her. “This isn’t the first time we’ve been alone.”

Mom pauses a moment.

“I know, sweetie, but it’s my job to worry.”

And worry mom does.

“Where did you get that dress, Lisa?” mom asks curiously.

There’s no suspicion in mom’s voice.

Lisa does look incredible in the dress though. It looks sort of like it’s made from two pieces; a short skirt that’s high at the waist in a dark blue color and a textured sleeveless top in a light blue tucked into it. The skirt bit is probably shorter than mom would have bought for Lisa. She would turn heads if she were showing off for anyone but you; so just one head instead.

“I haven’t seen that before,” says mom.

Lisa nods.

“Yeah, I bought it the other day with some savings.”

What you were now calling your nest fund.

“Oh, well it looks very nice,” mom compliments.

“Thanks mom.”

If you had dressed up, mom would have assumed you were going to a party and up to no good.

There’s a clunk from the entranceway followed by another and then another. The footsteps tell you it’s dad dragging a wheeled suitcase down the stairs.

“Homer!” says mom crossly towards the stairs. “You’d damage it doing that.”

“Oop! Sorry, Marge.”

Mom turns back to you.

“Okay, we’re running a bit late for Maggie’s sleepover so we need to get going.”

“No problem, mom,” Lisa says.

“Yeah, no problem.”

You and Lisa give Maggie a wave as she follows mom and dad out of the house. You and Lisa both try not to look like you’re watching mom, dad and Maggie get out of sight.

“So, dinner first?” you ask.

Lisa looks incredulous.

“Nope,” she says with a determined shake of her head.

You laugh and offer her a hand.

<^><^>

You close Lisa’s door behind you both as Lisa stands there nervously.

You’re half in the mind to fuck her in the dress while the other half wants to peel every bit of clothing off her. Then there’s another part that’s causing your heart to hammer away. After a few seconds of hungrily gazing at Lisa, another idea occurs to you.

“I want to eat you out.”

Lisa blinks at you.

“What?” she asks.

“I want to fuck you in that cute dress you’re wear,” you say honestly.

If Lisa weren’t already red in the face, you’re sure she’d be blushing.

“But I _really_ want to peel everything off you first too. So I want to do what I keep promising and eat you out as you’re dressed.”

“I –” Lisa objects, but then stops short.

You step up to her, your hands finding the soft skin of her thighs and running up under her dress to the edges of her underwear.

“You can tell me no if you want,” you dare her.

Lisa stares back, her face flushed. You’re sure she’s dripping and needy and you have the urge to torture her just a bit.

Lisa nods.

“Lie back on your bed, little sis.”

There’s a small sharp breath at naming her _sister_.

Lisa sits on the edge a little unsurely. Despite the promise and several blowjobs from her, you’d kept missing the opportunity to eat Lisa out.

“Lie back, beautiful.”

Standing over her, you push her dress up to reveal a set of blue lace panties. Lisa must have bought them online because mom would have freaked if she had been there. They won’t be enjoyed long though because you’re peeling them off.

The crotch sticks to Lisa slightly as you pull them off her legs, revealing Lisa’s dripping pussy to you. Her clit is sticking out of her folds, topped with sparse blond hair.

“You know, the quicker you cum for me, Lis, the quicker I put a baby in you.”

You don’t give Lisa a moment to respond before firmly licking her clit. Lisa gasps, her hips bucking slightly. You place your hands on her hips feeling the fabric of her dress under your fingers before giving her another lick. Your tongue starts at her opening and parts her pussy as you firmly work your tongue up. Your gland to have grabbed ahold; Lisa might have bucked into your teeth if you hadn’t.

The next few minutes just required you to keep licking and keep her hips still as you brought her closer. You doubt it was taking very long, it only felt like minutes, but you had no doubt that the thought of what came next was dragging Lisa to the finish line. Lisa’s hands were on your head, making sure you never let go, her fingers running through your sweaty hair.

“Baaarrt!” Lisa moaned.

Lisa’s fruitless bucking got stronger and her belicious pussy got wetter as she got closer.

“Bart! _Bart!_ – Oh! Oh!” Lisa wasn’t screaming, but she was still louder than any person normally would be in a home. “ _Ohhh! Ohhhh!”_

Suddenly you could feel Lisa spasm under your tongue.

“Baaarrrrt!” Lisa wailed.

You didn’t stop as Lisa kept cumming.

“S-stop, Bart!” Lisa eventually gasped out.

You finally relent and raise your head over the mound caused by Lisa’s dress. Her face is red and she’s coated in sweat. There’s that primal feeling again of _knowing_ you made her like that. _You_.

Getting up and taking a moment to inspect your handwork, you look over her hungrily. You and you’re sure Lisa too don’t have the patience to go through the song and dance of undressing you, so you pull your clothes off, leaving you naked.

Lisa’s eyes are hungrily on your cock before with a small yelp of surprise you carry Lisa further up her bed, her head now near her pillows. Staring down at you, you have a decision to make: you could do as you said you would and peel that dress off her, or you fuck her right now.

“Are you ready, Lis?” you ask her.

Lisa looks amazed that you had both come this far, that you were now about to _make_ a baby together.

“Y-yes,” she replied with a shuddering breath.

Maybe if she wanted a moment to recover you’d have peeled that dress off her, but with Lisa’s command, you’re not going to.

You climb up between Lisa’s legs and push her dress up to reveal her pussy. Lisa is breathing hard as you look into her eyes and see all the desire; the desire for you, the desire to _have_ children with you, the desire to carry your children. It’s all there.

Your hands are shaking as you take your cock as push it through Lisa’s folds, making sure to coat the tip of your cock in her slick wetness. You give your sister a reassuring smile before leaning over her and wedging your cock into position. Her eyes go wide as you begin to push.

Your first time had been a desperate attempt to go slow. This time, you were so nervous that everything required the careful measured approach. So now you could feel your foreskin peel back to its fullest extent as your pushed into Lisa, her slick tight walls gripping your cock as you committed the ultimate taboo. Eventually your balls touched her bum as your found yourself fully enveloped by Lisa.

That look of amazement was still on Lisa’s face, but now touched with contentment. She looked beautiful, the mother of your children and someday wife.

“I’m going to make you a mother, Lisa,” you whispered.

The amazement increased tenfold as you said those words.

“I love you, Bart,” Lisa said back breathlessly.

“I love you too.” No, not _someday_ wife. “You’re my wife, Lisa, my beautiful, incredible wife!”

You hadn’t thrusted, but Lisa made a pleasurable gasp anyway.

“I’m you wife!” Lisa started to babble quickly. “You’re my husband, Bart! And –” Lisa took a deep breath “– we’re going to make a baby now, right now.”

“I know,” you said thickly.

Lisa’s eyes were beginning to brim with happy tears. You pulled out slowly and then thrust back in.

“Ohhhh!” Lisa gasped.

You weren’t certain you could last a dozen thrust… you weren’t even sure you could get three or four out without cumming.

“I’m so close,” you tell her. “I’m so close to putting _our_ baby in your womb, Lisa. Cum for me, baby! Cum for me!”

You thrust again and Lisa makes a pleasurable wail. You can’t help it and bend down to silence her with a kiss. You can feel Lisa’s legs and arms wrap around you.

Another deep first thrust and Lisa shudders. You’re pretty certain this is it, that you’re going to fill Lisa with baby batter on the next thrust, but a part of your mind calls to hold out, to get one more.

You clench your core, desperately trying to hold out as you thrust again. You feel your ball twinge, like they are about to try contract. You thrust again, Lisa’s and your own bodies moving as one. Your balls clench again, this time eliciting a small twinge of pain.

Then you thrust the final time as you relent, your cock swelling. Lisa spasms around you as you bottom out and hold it there, your cum surging, splattering into your fertile wife and sister. You gasp, breaking the bond between lips.

“Lisa!” you groan as you give another small thrust, another health spurt of seed entering her.

Lisa can’t make a sound though, her mouth uselessly open.

“That’s it,” you say reassuringly. “That’s the baby batter you needed.”

You make another groan as another small spurt leaves you.

Your cock is still hard, but painfully sensitive as your hips still give Lisa a few tiny thrusts. You’re dazed, but know you’re going to have to pull out. Lisa makes a whine as you do before you put your arms around her, spooning Lisa from behind.

“I-I love you so much, Lisa,” you say. “I can’t even put it to words.”

Lisa doesn’t make a word, instead making a positive sounding whine.

She’s beautiful.

**Notes for the Chapter:**

> And this is the last of the prewritten chapters


	9. Radiant

**Loving Lisa**

**Part Nine:**

**Radiant**

A missed period seemed as good a sign as any to you, but you were happy to indulge Lisa as she took the pregnancy test. You suspected this isn’t what they meant by this, but you’re sure Lisa glowed as it came back positive.

You don’t wait to peel Lisa’s dress off her, instead you carry her to your room, push up her dress and push her underwear aside to fuck her on your bed. It’s not fast paced despite your desire, just slow and sensual.

Lisa cums before you, a satisfied smile on her face.

“Turn over, Lisa.”

Lisa does as ordered, waiting on all fours as you pull her underwear down her cute ass. You leave it around her knees as your line your cock up and push it into her.

“Ohh,” moans Lisa as you start thrusting.

Lisa gets lower and lower as you keep fucking her, her arms giving out. Your hands on her hips is the only thing keeping her ass at the right height.

“Come on, get up,” you tell her.

Lisa looks at you in confusion before your hands slide up under her arms and you pull her close. Hugging her from behind, you keep thrusting into her as your hands kneed her breasts through her dress.

You wonder what this sight will look like in a few months, if you will be able to look over her shoulder and see her round pregnant belly. The thought pushes you over the edge.

“Here is comes!” you tell her. “My beautiful pregnant sister.”

Lisa makes a loud whine and you feel her ripple before your cock is planted firmly into her to the hilt. Cumming in your pregnant sister, your wife-to-be is incredible, indescribable and impossible to really put to words.

“We’re going to be parents,” said Lisa in amazement in the afterglow.

“I know,” you agreed. “It’s incredible.”

You pull her into a deep kiss for a few moments and then separate.

“Let’s have a shower together, Bart,” suggests Lisa.

You smile and nod as she leads you there. She’s clenching here thighs together as you walk, trying to stop the cum from dripping on the floor, instead slicking up her thighs with it.

Once you’ve got the hot water on, you slip your arms around Lisa and look at her in the mirror. She smiles as you trace your fingers down her stomach. Lisa looked beautiful standing in front of you, her hands coming up to meet yours on the tiny baby bump, the slight firmness in her stomach, the proof of your love growing inside her.

“Isn’t it amazing to know _our_ baby is growing in there,” says Lisa.

She can’t hide the amazement in her voice.

“I know,” you agree then shake your head with a smile. “I’m just glad you love me back.”

Lisa’s smile is broad as she stares back at you.

“So am I.”

At this point your cock is back with full force, it’s pressed between you and Lisa’s ass. She slips out of your arms and turns, surveying you a moment, her eyes on your cock before leading you into the shower. She strokes your cock several times under the warm water before – using you as support – gets on her knees.

She glistens beautifully in the flowing water as she envelops the head of your cock with her mouth. Again, you’re back to imagining what she will look like in serval months in the same position, visibly pregnant with your child.

You groan as Lisa’s tongue traces the bulbous edge of your cock, her eyes looking up to meet yours. You push your fingers though Lisa’s short wet hair as her hands begin to stroke your shaft.

“Oh – you’re so good at this,” you tell her.

You’re sure you can see pride in Lisa’s eyes.

“I’m so lucky to –” what you were saying is cut off as you groan again. “– so lucky to have you Lisa.”

Your hips start moving on their own accord, meeting Lisa as jerks you off, your cock in her mouth.

“My – my beautiful pregnant little sister.”

There’s love in Lisa’s eyes. You absolutely share it with her.

“God, you’ll look even more beautiful as our child grows in you.”

Your hips thrust more firmly now and Lisa’s tongue picks up the pace.

“This is it,” you grunt.

Lisa switches to making her best effort at deep throating, your sister pleasuring your shaft with her lips. You can feel your balls contract and your cum surge through you. Her lips around the head of your cock she returns to stroking you as your cum fills her mouth.

As the pulses of cum subside, you can see Lisa’s lips part slightly, letting a small dribble of cum run down her chin before she pulls back slightly, letting your cock spring free from her lips. She looks you in the eyes as her mouth opens, the healthy load of baby-batter pooling in her mouth, before she swallows.

Lisa licks her lips and tries to get the cum on her chin. Failing to reach it with her tongue, she raises a hand to wipe it off, but before she does you reach out and wipe it up for her with a finger, placing Lisa’s reward in her mouth.

“I have to be the luckiest man alive to have you, Lisa.”

Lisa smiles brightly up at you.

<^><^>

Lisa’s only twelve weeks along but has already gone up a cup size. Lisa’s breasts are beautifully round now on her slender frame. She was already beautiful, but there’s something to knowing she’s going through these changes because of the baby you made together and now growing inside her.

“I definitely need some new bras,” she says as she hooks together her bra band.

“I kind of like it,” you admit, your eyes looking over her breasts spilling over the cups slightly.

Lisa gives you the same wonderful, satisfied smile she always gives you when you admit you like something about her. She lets you ogle as she puts on her underwear, your eyes tracing over the small baby bump now visible. You can’t deny worrying now you’re both back at school, that something could happen to Lisa when you’re separated by grade and classroom. Lisa likes reminding you that she’s not helpless pregnant – at least, not yet.

As Lisa throws on a sundress you regret you can’t satisfy Lisa this morning, but that would increase the already substantial risk you’re both facing today.

“All ready?” you ask.

Lisa nods nervously.

You had both rehearsed this, practiced not looking like lovers, on looking like you’re just a concerned brother. Getting off the bus you have to remind yourself not to take Lisa’s hand.

As you get closer you pause at Lisa giving an annoyed sigh, an unhappy frown on her face. Up ahead you can see the protestors with their signs and clearly waiting to hand out whatever religious nonsense anti-abortion protestors do.

“Don’t they know Planned Parenthood does other things?” Lisa says quietly.

“These nutjobs aren’t exactly know for their intelligence, Lis.”

Lisa gives a small laugh of agreement.

Besides just being obnoxious, you didn’t need someone who might know you spotting you or Lisa. Knowing your luck, Flanders could even be there. You admit you’re gleeful for the day either Rod or Todd comes out as gay and the look on Flanders’ face when it happens, but you don’t need him knowing about this. It would be a fucking nightmare.

“We might be able to get in the back,” you suggest.

Lisa gives you a skeptical look. To be fair to her, that’s probably the first thought of anyone dodging the protestors.

“We should at least take a look.”

Lisa agrees and you start walking around the block.

<^><^>

Unluck would have it, Rod Flanders is standing out back with a sign.

“Nah, I think I can distract him.”

“You sure?” Lisa asks worriedly.

“It won’t be too hard,” you say reassuringly. “If he asks why I’m poking about I can just tell him I’m up to no good. I’m sure he’ll believe it in an instant after the dribble Flanders has fed him.”

Lisa still looks skeptical.

“Really, I bet he will try to preach to me even. He’ll want backup and will probably lead me around front so he can show off his converting skills to his dad.”

You nod emphatically.

“Okay,” says Lisa.

“It will be fine, Lis. Worst come to worst it doesn’t work and we think of something else.”

With Lisa out of sight you pretend to spot Rod and wander over.

“Oh hey, Rod,” you greet. “What you doing around here?”

Rod’s surprised to see you.

“H-hey Bart.”

You wait for him to continue but he doesn’t.

“I’m surprised to see you in this part of town.”

It’s certainly not the nicest bit of town. Rod clearly doesn’t like my implication about why he’s here though.

“Oh – well I’m here with dad, doing the Lord’s work!”

He holds up his sign. It’s not a nice image he’s got glued to it. You try not to show too much on your face looking at it.

“So,” you say, turning back to Rod. “Not after the free condoms then?”

Rod freezes and then on cue blushes. Flanders might have decided to keep his impressionable children away from you and Lisa when he figured out you weren’t converting, but it’s clear Flanders hasn’t lost his sheltered touch.

“N-no!” Rod exclaims. “Pre-marital _sex_ is a sin!”

Rod whispers the word _sex_ like a seven-year-old saying it for the first time.

You adopt a baffled look.

“Really? How else are you supposed to fill that void in your heart?”

There’s a moment before Rod looks like he’s come to a realization.

“Rather than get an unfulfilling icon of sin, would you like to have some cake and fruit juice?” asks Rod enthusiastically. “We’ve got plenty up front! It’s free.”

I would not be shocked if this is the first time he’s even thought his preaching might have touched a heart.

“Cake?” you ask.

“Yep! Healthy banana cake.”

That’s… actually not bad as far as “healthy” cakes go.

“Alrighty then,” you agree.

Rod looks like he’s jumping with joy as he leads you around the front.

<^><^>

You drown out Flanders’ preaching as you eat the banana cake and drink your juice. You might be fifteen, but you can still enjoy a fruit box. You find the droning is best handled by imagining your sister.

“Well, thanks for that,” you say, turning on your heel and walking back to the alley.

Flanders’ and his two sons seem shocked that you do so mid-sentence into the speech. You take the opportunity to disappear out of sight around a corner before running off and reach the back door of the clinic before slipping inside. Rod never had the chance to get back to his watch post before you did.

There’s a nurse or someone at the counter giving you a curious look.

“Sorry, just had to distract the protestor out back,” you explain.

There’s a small amount of surprise and then appreciation.

You start mentally steeling yourself to play brother as you walk the short distance to the waiting area. Lisa’s thankfully there, looking nervous.

“All good?” she asked quietly.

“Yep, sis,” you say loudly enough for the staff member nearby to hear.

Lisa gives a sigh of relief.

“Glad you had me along then?”

Lisa nods. She gives you an appreciative smile.

Noticing the staff member watching your interaction with Lisa you give her a knowing look.

“One of the guys out front is our neighbor,” you say distastefully.

She visibly cringes.

“I’m glad Lisa has you for a brother,” she says after a moment.

You shrug casually.

“Gotta help family,” you say like it’s the most obvious thing in the world.

The staff member comes over a few minutes later with a clipboard and some forms for Lisa to fill out. Not long after a doctor or something called Lisa’s name and she disappeared into one of the rooms.

“Do you know anything about the boy?” the lady asked a few minutes later.

You look up at her from your phone.

“Not really,” you reply with a shrug. “Lisa asked me to cover for her when she snuck out to a party. All I know is he was a lot older than he let on and wasn’t in town long.”

She nodded understandingly.

“Typical,” you’re pretty sure you heard her mutter.

You go back to your phone.

“Do you normally cover for her like that?”

“We have a system; I cover for her and she covers for me.” You pause for dramatic effect. “Though it’s usually me that’s sneaking out. Lisa’s the straight-A student, not me.”

The lady looked saddened at the statement.

“Lisa’s smart and she’s got good support, she’ll bounce back,” you say reassuringly. “I’ll be there to help at least. Mom and dad probably too.”

<^><^>

You go out the door first to check for any Rod-shaped people.

“We’re clear, sis.”

They’d given Lisa a lot of documents. You don’t discuss anything on the bus, but you can see a hint of Worry in Lisa’s features. As you get home and close the door behind you, you quickly pull Lisa into a comforting hug.

“Everything okay?” you ask.

Lisa nods into your chest.

“Yeah,” you heard her quietly say.

When you finally separate you lead Lisa to the loungeroom and take a seat, cuddling on the couch.

“What did they say?”

Lisa takes your hand before replying.

“Ultrasound looked okay. Blood test won’t come back for a few days.”

It’s a good start.

“I think I got my worry right. I just talked about wanting to be sure.”

You give a small laugh.

“It probably helps you really are interested in all the technical stuff,” you say.

Lisa looks up from your shoulder, bright eyed.

“Just one of the many reasons I love you,” you tell her.

You want to lean in and kiss her at that moment but you do need to let her finish. In recompence you lead yours and hers joined hands to her stomach and place your hands over her growing bump. Lisa looks back at you lovingly.

“I’ve got to go back in a few weeks for those tests.”

You nod understandingly before worry crosses her face.

“They… know about how old I am,” says Lisa carefully.

Your smile turns painful for a moment.

“She didn’t buy my age on the form.” Lisa nervously shuffles slightly. “Told me off actually for lying about it.”

You give a small nervous chuckle.

“Anyway, she said she has to report me to child protection. They’ve got to report anyone who’s under a certain age pregnant. They’ll want to check the house out, look for any obvious abuse and such.”

“Ah,” is your simple reply.

As everyone consented and there was no coercion, you’re sure they’ll find nothing, but that worry is still there.

“So, we’ve got to tell mom and dad soon?”

Lisa shakes her head.

“The doctor said she’ll hold off for a while if I keep all my appointments. She’s not supposed to, but she said she will.”

That’s better than you expected.

“So, nothing to worry about then?” you ask with a reassuring smile.

Lisa nods, a small smile on her face. You lean down to kiss her, enjoying the moment of overcoming the first hurdle. Lisa pushes you apart though, an excited look on her face.

“Here, take a look!” she says excitedly, looking though the stack of papers she was given.

She pulls out the ultrasound.


End file.
